Studying the Effect of the Amount of Source Materials and Water to Binder Ratio on Chloride Ions Ingress in Alkali-Activated Slag Concretes

Document Type : Research Article


1 1 Faculty of Civil and Environmental Engineering, Amirkabir University, Tehran, Iran

2 Faculty of Civil and Environmental Engineering, Amirkabir University, Tehran, Iran

3 Faculty of Civil Engineering, University of Tehran, Tehran, Iran


Due to the high amount of CO2 emission through the production of cement and great energy consumption in the cement industry, one of the most important issues in concrete technology is to find out an appropriate replacement for Portland cement. Alkali activated materials are the new approach for solving this problem. In fact, alkali activated concrete consists of an inorganic structure containing two parts: source material and alkaline activator liquid. In this study, the effect of the amount of source material and water to binder ratio on chloride ions ingress was evaluated. For this purpose, 5 mix designs were used to make alkali activated slag (AAS) concretes and for activating slag, 6 molar potassium hydroxide and sodium silicate solutions (wt. ratio: Na2O/SiO2 = 2.33) were employed as alkaline activator liquid. Additionally, one mix design was dedicated to ordinary Portland cement (OPC) concrete for the sake of comparison. The properties of AAS concretes were examined by means of slump loss test, measurement of compressive strength at the ages of 1, 7, 28, 90 and 180 days and also capillary water absorption test at 7, 28 and 90 days. Furthermore, chloride ions penetration was measured through electrical resistivity test, rapid chloride migration test (RCMT) and resistance against chloride ions diffusion test according to NT Build 443. The results indicated that the performance of water to binder ratio and also the amounts of source material were comparable to that of ordinary Portland cement (OPC) concretes. Additionally, alkali activated slag (AAS) concretes had higher compressive strength and also superior durability against chloride ions penetration compared to OPC concretes.


Main Subjects

[1] P. K. Mehta, P. J. Monteiro, Concrete: microstructure, properties, and materials. New York, McGraw-Hill (2006).
[2] A. A. Ramezanianpour, A. Kazemian, M. Sarvari, B. Ahmadi, Use of Natural Zeolite to Produce Self-Consolidating Concrete with Low Portland Cement Content and High Durability, Journal of Materials in Civil Engineering, 25(5) (2012) 589–596.
[3] A. A. Ramezanianpour, A. Zolfagharnasab, F. Bahman Zadeh, M. R. Pourebrahimi, Fresh Properties, Compressive Strength and Chloride Ion PenetrationResistance of Self-Consolidating Concrete Containing Natural Pozzolan. The Fifth International Conference on Construction Materials (CONMAT 15), Whistler, Canada (2015).
[4] J. Davidovits, Chemistry of Geo-Polymeric Systems, Terminology, Geopolymer International Conference, France (1999).
[5] X. C. Pu, C. C. Gan, S.D. Wang, C.H. Yang, Summary Reports of Research on Alkali-Activated Slag Cement and Concrete, Chongqing Institute of Architecture and Engineering, Chongqing, (1988) pp. 1–6.
[6] C. Shi, P.V. Krivenko, D. Roy, Alkali-Activated Cements and Concretes. Taylor & Francis, New York (2006).
[7] S.D. Wang, X. C. Pu, K. L. Scrivener, P. L. Pratt, Alkali-Activated Slag Cement and Concrete: a Review of Properties and Problems, Advances in Cement Research, 7(27) (1995) pp. 93–102.
[8] A. A. Ramezanianpour, T. Parhizkar, A. R. Pourkhorshidi, A. Raeis Ghasemi, Assessing Concrete Durability with Different Cements and Pozzolans in Persian Gulf Environment, BHRC Publication (2006).
[9] R. D. Brown, Design Prediction of the Life of Reinforced Concrete in Marine and Other Chloride Environments, Durability of Building Materials, Elsevier Scientific Publishing Co., Amsterdam, 3 (1982).
[10] C. Aria, N. R. Buenfeld, J. B. Newman, Factors Influencing Chloride Binding in Concrete, Cement and Concrete Research, 20(2) (1990) pp. 291– 300,
[11] A. O. Saud, Performance of Alkali-Activated Slag Concrete, The University of Sheffield (2002).
[12] F. G. Collins, J. G. Sanjayan, Workability and Mechanical
Properties of Alkali Activated Slag Concrete, Cement and Concrete Research, 29(3) (1999) pp. 455–458.
[13] ASTM C143/C143M – 13, Standard Test Method for Slump of Hydraulic-Cement Concrete, ASTM International, West Conshohocken, PA (2013).
[14] EN 480-5, Admixtures for concrete, mortar and grout. Test methods. Determination of capillary absorption, European Standard (EN) (2005).
[15] Designation: FM 5-578, Florida Method of Test for Concrete Resistivity as an Electrical Indicator of its Permeability (2004).
[16] NT Build 492, Chloride Migration Coefficients from Non-Steady-State, Nord test method (1999).
[17] NT Build 443, Concrete, hardened: Accelerated chloride penetration, Nord test method (1995).
[18] M. R. Maddah, The effect of different solutions in geopolymer cement production with two types of pozzolan and evaluation of mechanical properties and chloride ion penetration in these concretes, M.Sc. Thesis, AmirKabir University of Technology (2013).